title: Self-aligned ballistic n-type single-walled carbon nanotube field-effect transistors with adjustable threshold voltage.
abstract: Near ballistic n-type single-walled carbon nanotube field-effect transistors (SWCNT FETs) have been fabricated with a novel self-aligned gate structure and a channel length of about 120 nm on a SWCNT with a diameter of 1.5 nm. The device shows excellent on- and off-state performance, including high transconductance of up to 25 microS, small subthreshold swing of 100 mV/dec, and gate delay time of 0.86 ps, suggesting that the device can potentially work at THz regime. Quantitative analysis on the electrical characteristics of a long channel device fabricated on the same SWCNT reveals that the SWCNT has a mean-free-path of 191 nm, and the electron mobility of the device reaches 4650 cm(2)/Vs. When benchmarked by the metric CV/ I vs Ion/Ioff, the n-type SWCNT FETs show significantly better off-state leakage than that of the Si-based n-type FETs with similar channel length. An important advantage of this self-aligned gate structure is that any suitable gate materials can be used, and in particular it is shown that the threshold voltage of the self-aligned n-type FETs can be adjusted by selecting gate metals with different work functions.
authors.affiliation: Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China. zyzhang@pku.edu.cn
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zhang
authors.forename: Sheng
authors.initials: S
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Ding
authors.forename: Xuelei
authors.initials: X
authors.lastname: Liang
authors.forename: Tian
authors.initials: T
authors.lastname: Pei
authors.forename: Jun
authors.initials: J
authors.lastname: Shen
authors.forename: Huilong
authors.initials: H
authors.lastname: Xu
authors.forename: Qing
authors.initials: Q
authors.lastname: Chen
authors.forename: Rongli
authors.initials: R
authors.lastname: Cui
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Lian-Mao
authors.initials: LM
authors.lastname: Peng